Quick-break switching mechanism.



H. G. WELLMAN,

QUICK BREAK swmcame MECHANISM.

APPLICATION FILED FEB.5,1012, 77 380 Patented Nov. 4, 1913.

3 SHEETS-SHEET 1.

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1,077,380, Patented Nov. 4, 1913.

3 HEETSSHEBT Z.

I 20 72 KG )1 State of Ohio, have invented a HOLLEY G. WELLMAN, FCLEVELAND, oHIo.

QUICK-BREAK SWITCHING MECHANISM.

To all 'wlwmz't may concern:

Be it known that I, HoLLEY G. WELLMAN, a citizen of the'Unit-ed States,residing at Cleveland, in the county of Guyahogaand certain new anduseful Improvement in Quick-Break Switching Mechanism, of which thefollow-- i ing is a full, clear, and exact description.

i illustrated This invention relates to improvements in quick breakelectric controllers or switch mechanisms, and particularly to that typein a patent to; Thomas W. Thomas, for quick breaking electric switchmechanism, No. 1,021,016,1Vlarch 26th, 1912.

I In the above mentioned application, there is disclosed a controllerincluding a number of pivotally mounted switch levers .or arms which areadapted to be closed in a predetermined order by cams on a manuallyoperable cam shaft when the latter is turned in one direction, and to beopened with a snap action by springs acting on the switch arms, whenthecam shaft is turned in the reverse direction, and when certain raised oroperative portions of the cams are moved out of engagement with theswitch arms.

The present invention is, in one aspect an improvement over this thoughcertain features are capable of it has for its main object to broaderand more general application, and provide means whereby arcing at thecontacts is decreased and is fact practically eliminated.

In accordance with the present invention, to ellmmate arcing at thecontacts of a switching mechanism or controller having one or moreswitch levers which are adapted to be actuated by mechanical closingdevices, such as cams on a cam shaft and to be opened by springs orequivalent means, I

.prov de means preferably in the form of magnets which acting .on thelevers hold the contacts in engagement until the switch and quickly,

closing deviceshave moved out of engagement with the levers, and thenrelease the latter so that they may be moved by the springs quicklytofull open osition. thus temporarily holding t e levers in closed"positionor with the contacts in en gagement until after the switchclosing d'e. vices have moved out of engagement with the levers, thelatter may be opened freely ment of'the controllerorswitch handle.

My invention may be further briefly sum-' marized as consisting in certan novel de Specification of Letters Patent. Application filed February5, 1912.

controller, al

and D in this case being ported on the shaft E regardless of therate ofmovethree being Serial No. 675,505.

tails of construction and combinations and arrangements of parts whichwill be dc scribed in the specification and the appended claims.

Referri-n-g'now to the figures of the draw-.

ing, .Wherein I have shown my.invention applied to a motorcontroller,'Figure 1 is a plan view-of the controller';'Fig. 2 is an endview of the same looking toward the end at the bottom of Fig. 1; Fig. 3is a transverse sectional view along the line 33 of Fig. 1; Fig. 4 is adetail sectional view of a portion of the magnet controlling switch online 4 4: of Fig. 1; Fig. 5 I view showing conventionally the controllerand motor, the connections between the same and the connections for themagnets.

Referring nowto the drawings, 10 represents an insulating base on whichis supported by a number of brackets-l1, a manually operable cam shaftA, consisting preferably of a number of alined sections A, A A which aresecured together but are insulated from one another by insulating disksB and B, thesection A extending beyond the insulating baseand havingprovision for connection with an operating or controller handle, notshown. This cam shaft A is provided with a number of cams C, C, C C C C(1 ,0 C 0", C and C, said cams being preferablycast integral with therespective the cam shaft and each being provided with an are shapedraised or operating-portion 0' adapted to engage the switch levers orsuitable rollers provided thereon and with recessed portions 0 Theraised portions of the difi'erent cams are of different arcuate lengthsand the connecting portions between the raised and recessed portions arepreferably slightly curved, as shown at 0 Arranged below or in theplanes of the cams C to C are a number of switch levers or arnls D,-D2D37 D57 D67 D7, a DD D100 and D, which are pivotally mounted on twoalined shafts E", E which are also supported by the brackets 11, thelevels D pivota'lly supsubstantially Patented Nov. 4, 1913.

sections A and A of and the other levers set forth in is a dlagrammatic-D toD being 'pivotally supported on the shaft E It maybe here statedthat the levers, D to D are utilized for connecting the-armature and thefields of the motor to the. line or current supplying conductors,

adapted to be closed simultaneare connected sprin gs ously when thecontroller handle is moved forwardly to the first operative position,and three being adapted to be closed. when the controller handle ismoved to the first operative position in the reverse direction toreverse the motor, and the switch arms D to D are employed for cuttingresistance sections in or out of the motor field circuitfor eitherforward or reverse movement of the controller handle and successively orin sequence in a well known manner.

All the switch levers are provided at their rear ends with extensions 12to which '13 which tend to open said levers, and forwardly of thesupporting shafts E and E the levers are provided with rollers 14,having trunnion-like supports which engage within suitable bearingopenings in the side walls of the levers, the levers being somewhatchannel -or U- shaped in cross section. These rollers are so locatedthat they will be engaged by the cams C to or switch levers and holdthesame closed as long as the arc-shaped raised portions 0 are inengagement with said rollers. The levers D to D are preferably providedat their forward ends with laminated contact brushes 15, the forwardends of which are beveled and are adapted to engage inclined portions 16of stationary contact members 16 which are secured to the base 10, andare provided also with spring contact fingers 17 which are provided attheir free ends with auxiliary contacts 18 adapted to engage stationaryauxiliary contacts 19 which are supported on the bracket 16, as shownclearly in Figs. 2 and 3. The auxiliary contacts 18 are adapted toengage the contacts 19 prior to the engagement of the laminated contactbrushes 15 with the stationary contacts 16, and said auxiliary contacts18 are.

adapted to leave or be separated from the contacts 19 after the contacts15 are separated from the contacts 16, as in the customary manner. Theswitch levers D to D are provided at their forward ends simply withcontact fingers 20 provided with contacts 21 which are adapted to engagestationary contacts 22 also mounted on the base 10. g

It will be apparent that by turning the shaft successively through theforward positions or successively through thereverse positions, theswitches will be closed by the engagement of the raised or operatingportions 0 of the cams with the rollers 14:, the

levers being actuated by the cams so as to cause the engagement of themovable contacts with the stationary contacts, and being held in' theirdownward or closed positions as long as the raised'portions of the camsare in engagement with the rollers. It will be apparent also that whenthe raised will be operated G which close the switches of said strip 33extending over- 0 of the cams are moved out of engagement with therollers 14:, may be opened by the springs, the rollers moving into therecessed portions 0 of the cams. It will be notedalso that if theopening movement of all'the levers is dependent wholly upon thedisengagement of the raised portions of the cams and the rollers 14, avery appreciable amount of time will be required for the openingmovement, even though the inclined portions 0 of the cams are made asabrupt as possible. Therefore even though the cam shaft were moved fromfirst operative position (forward or reverse), to off position asquickly as it could be moved by hand, there would nevertheless beconsiderable arcin at the contacts of those switches which d1sconnect'the motor armature and field from the line circuit.

In order to avoid arcing at the contacts when the controller is moved tooff position so as to disconnect the motor armature and field from theline circuit, I provide means whereby the opening of the switch leversat which arcing would occur is rendered independent of the actualdisengagement of the cams and the corresponding rollers 1 1. This isaccomplished in this caseby pro viding in cooperative relation with theswitch levers D to D at which the arcing would ordinarily take place aplurality of magnets 23, one of which is arranged below or in line witheach of these switch levers so as to hold the levers in closed positionor partially closed position until the cams which actuate the saidlevers have reached positions such that the portions 0 are quite out ofengagement with the corresponding rollers 14: so that when the magnetsare deenergized, the levers may be opened freely by the springs 13.These magnets cooperate with armatures 24, which are loosely attached tothe levers and are connected to the latter by stems 25 which passthrough openings in the levers, as shown most clearly in Fig. 3, coilsprings 26 serving to normally hold the arinatures 24: away from theswitch arms.

The magnets are energized and deenergized or connected and disconnectedfrom the line conductors .to be referred to resently by means of aswitch D which is a apted to be opened 'and closed by the cam O on theend of the camshaft section A. This switch D includes a bar or strip 28which is adapted to be rocked or tipped in one direction or the other bythe cam G and is pivotally connected midway between its ends to a pin orplunger 29 which is slidably mounted in a bracket 30 and is yieldinglypressed outward by a spring 31. The member 28 is rovided at each endwith a cross bar 32 of insulating material, to which is connected acontact strip 33 with the ends the top of 1 'theinsulating cross member32. Each end of the' movable switch member of switch D isadapted-tocooperate with three-separate stationary the magnets and theswitch D, it maybe well being had'to Fig. ranged on the cam shaft'thatwhen the latter or the controller-handle. is moved to the by- -conductor45 conductor '46, all the sections of wardly from off to; the ,tion, theswitch arms to point out the order in which "the switch levers areopenedand closed, and the man'- ner in which the connections are made'betweenthe controller and motor, reference 5. The cams are so arfirst-operativeposition in the forward direction, switch levers D, D and D are closed.This connects the motor field and armature to line or main currentsupplying conductorswhich are designated 40 and'41,with

all the sections of 'the'resistance-R im the field circuit. Theconnections andthe circuit are as follows -assuming that the conductor.40 is a positive conductor. Current passes from this conductor-by aconductor 42 to the shaft section E; thence through switch arm D I andcondu'ctor:43 to one terminal of the motor armature 44; thence and othersuitable connections toswitch arm D section E to the switch arm D;

the resistance R, and by conductor 47 to one side of the motor field46;'and thence by conductor 47 a to the-other main current su'pplyingconductor 41.. As-the controller arm is moved forwardly through the otheroperative posito D are operated. successively so as to cut out differentresisttions,the switch arms D ance sections. I When the controllerhandle is moved back' first operative posi- D D .remain open, and theswitches 'D ,"D and D are' simul taneou'sly closed. This reverses thedirection' of'currentthrough the motor armature with all the resistancesections in the field circuit so that the motor-will beoperated in thereverse direction at its lowestspeed. When the controller handle ismoved'backward to the first operative position, the circuit through thecontroller and motor is as followsz from the main supply conductor 40 tothe shaft section .E thence by switch lever D and conductor 45 to oneterminal of the motor armature; thence 'from the opposite terminal ofthe motor-armature by conductor 43 and aconnection 43 toswitch 'leve'r Dand to shaft section E and from shaft section. E

to switch lever B; thence designated 34, 35, and 36,,

stationary theme by the shaft thence by by conductor 46, sections ofresistance Rand conductor 47 to one terminal of the field and thencefrom theopposite ter-' minal of the field winding by conductor 47winding to the main current supplying conductor 41. \Vhen the controllerhandle is moved back- .wardly, through the other operative posi' to Dare closed tions, the switch levers D successively and the differentresistance secti'o'ns are successively cut out of the field circuit.

NVhen the controller handle or cam shaft is in offposition, thecam Cwhich controls the switch D is in a; position substantially at rightangles to the member 28 of the switch D or engages at substantially the'middle portion-of this member 28 so as 'to hold the same out ofengagement" with the contacts at each end thereof. When, however, thecontroller handle is moved from off position toward the first operativeposition, wa'rdly, the member 28 of switch D is rocked by the cam O sothat the contact members atone end or the other: thereof engage with thecorresponding set of stationary contacts so as to energize the magnets23 by connecting the'same to the main supply conductors 40 and 41. -Whenthe switch member 28 is rocked in either direction, the circuit throughthe magnets may be traced as follows: from the maincond-u'ctor 40byconductor 42 to shaft section E, and from the shaft section E byconnection 50 to themember 28 of the switch D thence to one or the otherstationary contacts 35 or 38 of switch D; thence by connections '52.toand through the coils of all the magnets 23; thence by connections 53 toeither of the end contacts 34 or 37 thence by one of the cross contactmembers 33 of the switch D to one of the end stationary contacts 36 or39 and by conductor 54 to the main conductor 41. These magnets willremain energized while the controller handle is moved forwardly orrearwardly through its different operative positions and during aportion of its movement from either first forward or first backwardposition to off position. In other words the magnets remain energizeduntil afterthe cams C, C and C, which had previously actuated andretained in closed position the switch levers D, D and D or until afterthe cams C C and G which had previously actuated and retained in closedposition the switch levers D D and D move out of engagement or out ofoperative relation with the corresponding rollers on the switch levers.Just before the controller handle reaches off position, the magnets aredecnergized by the action of the cam C on the magnet controlling switchD, and. the switch levers which (were held in closed positionare thenquickly opened by of the middle cover all modifications which invention.

the corresponding springs 13. When the cams move out of engagement withthe rollers, the switch levers have a slight opening movement until theyengage suitable stop members on the outer ends of the pins 25, whichsupport the magnet armatures 24, this movement being sufficient toseparate the laminated contact brushes 15 from the stationary cont-acts.The magnets, however, by the pull on the armatures 52A, prevent furtheroutward movement of the switch levers until after the cams have movedout of operative relation with respect to the rollers, and until afterthe magnets are deenergized when the auxiliary contacts are separatedvery quickly in the manner above stated. By thus providing means forretaining the switch. levers closed or in positions such that theauxiliary contacts are in engagement, independently of the cams, anduntil the cams are free of the rollers, and by then releasing the switchlevers so that they may be opened with a snap action by the springs,sparking is minimized and the main object of my invention, as stated atthe beginning of the specification, is tained.

While I have shown my invention applied to a motor controller of oneparticular type, it can be very effectively employed in other forms ofcontrollers, and other types of switching apparatus employing any numberof switch arms, and I aim in my claims to do not involve a departurefrom the spirit and scope of my Having thus I claim is:

1. In a quick break electric switch, the combination of a movable switchmember, a movable switch closing deviceadapted to engage the said memberto cause the closure of the switch, and to permit the opening of theswitch when moved out of engagement with said switch member, and meanscomprising a magnet for holding the switch closed independently of saidclosing device until after the latter is moved a predetermined distanceaway from said switch member.

2. In a quick break electric switch, the combination of a movable switchmember, a switch closing device adapted to engage said member to closethe switch and to permit the opening of the switch when moved out ofengagement with said member, means comprising a magnet for holding theswitch closed independently of said device, and means for deenergizingsaid magnet when said device is moved a predetermined distance out ofengagement with said member.

3. In a quick break electric switch,'the combination of a mgvable switchmember, means for moving said switch member in described my invention,what one direction to open the switch, a switch,

closing device adapted to cause the closure of the switch whenthe deviceis moved in one direction, and to permit the opening of the switch whensaid device is moved in the reverse direction, and means independent ofsaid device for temporarily preventing the opening of the switch untilafter said device is moved a predetermined distance in said reversedirection.

4:. In a quick break electric switch, the combination of a pivotedswitch lever, means for moving said lever in one direction to open theswitch, a switch closing device adapted to engage said lever and toclose the switch when said device is moved in one direction and topermit the opening of the switch when said device is moved in thereverse direction, and means separate from said device for preventingthe opening of the switch until said device is moved out of engagementwith the lever, a predetermined distance in said reverse direction.

5. In a quick break electric switch, the combination of a movable switchmember, means for moving the same in one direction to open the switch, aswitch closing device adapted to close the switch when said device ismoved in one direction and to permit the opening of the switch whenmoved in the reverse direction, means comprising a magnet for holdingthe switch closed, and means for deenergizing said magnet when saiddevice has moved a predetermined distance in said reverse direct1on.

6. In a quick break electric switch, the combination of a movable switchmember, means for moving the same in one direction to open the switch, amovable switch closing device adapted when moved in one direction toclose the switch, and when moved in the reverse direction to permit theswitch to be opened, a magnet for holding the switch closed, and meanscomprising a switch for causing the deenergization of the magnet whensaid device is moved a predetermined distance in said vreversedirection.

7. In a quick break electric switch, a pivoted switch lever, a springfor moving the same in one direction to open the switch, a rotatableoperating shaft, a device on said shaft for moving the said lever toclose the switch, a magnet for retaining the lever in closed positionafter the said device is out of operative relation with said lever, anda switch actuated by said shaft for causing the energization anddeenergization of the magnet.

8. In a quick break electric switch, the combination of a switch lever,a spring for moving the same in one direction, a rotatable operatingshaft, a cam on said shaft for actuating said lever to close the switch,a magand is moved 7 ing the net for preventin by said cam unti operativerelation the opening of the switch after the latter is out of with saidlever, and a switch actuated by said operating shaft for controllingsaid magnet.

9. In a quick break electric switch, the combination of a switchlever, aspring for movsame in one direction to open the switch, a rotatableoperating shaft, a cam on said shaft for actuating said lever to closethe switch, a magnet for holding said switch lever in closed positionindependently of said cam, a switch for controlling said magnet, and acam on said shaft for actuating said last named switch.

10. Ina controller, the combination of a plurality of pivoted switcharms, springs for moving said arms in one direction to open position, arotatable operating shaft, cams or moving said arms in the oppositedirection to closed position, means comprising a plurality of magnetsfor preventing the opening of the arms, until after the cams are free ofsaid arms, and a switch controlled by said shaft for causing theenergization or denergization of the magnets.

11. In a quick break electric switch, the combination of a switch lever,a roller on said lever, a spring for moving the lever in one directionto open the switch, a rotatable operatin shaft, a cam on said shaftprovided with a recessed portion and with a raised portion adapted toengage said roller so as to close the switch and to holdthe same inclosed position, means for preventing the opening of the switch by saidspring until after the recessed portion of the cam is opposite saidroller, and means for causing the release of'said switch lever, wherebythe same may be opened with a snap action by said spring.

'12. In a quick break electric switch, the

combination of main and auxiliary stationary contact members, a switchlever having main and auxiliary contact members adapted to engagerespectively the main and auxiliary stationary contact members, a springfor moving the switch lever in one direction to open the switch, arotatable operating shaft, a cam on said shaft for actuating the saidlever to close the switch, and a magnet acting on said lever forpreventing the separation of the auxiliary contacts by said spring untilafter the cam is out of operative relation with said lever.

13. In a switching apparatus, a movable switch member, a switchoperating device adapted to move said switch member in one direction, toclose the switch when said operating device is moved from off positionin either direction, and means separate from said device for temporarilyholding the switch closed until said device is moved a predetermineddistance toward ofli' position.

In testimony whereof, I hereunto aflix my signature in the presence oftwo witnesses.

HOLLEY G. WELLMAN.

Witnesses:

H. R. SULLIVAN, A. F, KwIs.

